April 2009 arXiv papers — page 3
Showing 201–300 of 4,924 papers
K. Hagino, H. Sagawa, T. Nakamura, S. Shimoura
We discuss the energy and angular distributions of two emitted neutrons from the dipole excitation of typical weakly-bound Borromean nuclei, $^{11}$Li and $^6$He. To this end, we use a three-body model with a density dependent contact interaction between the valence neutrons. Our calculation indicates that the energy distributions for the valence neutrons ar
Relativistic Theory of the Electric Dipole Moment of an Atom due to the Electric Dipole Moment of an Electron
physics.chem-phDebashis Mukherjee, B. K. Sahoo, H. S. Nataraj, B. P. Das
The relativistic theory for the electric dipole moment (EDM) of paramagnetic atoms arising from the electric dipole moment of the electron is presented. A novel approach using the relativistic coupled-cluster method that incorporates the residual Coulomb interaction to all orders and a weak parity and time-reversal violating interaction to one order has been
Chemical potential of quadrupolar two-centre Lennard-Jones fluids by gradual insertion
physics.chem-phJ. Vrabec, M. Kettler, H. Hasse
The gradual insertion method for direct calculation of the chemical potential by molecular simulation is applied in the NpT ensemble to different quadrupolar two-centre Lennard-Jones fluids at high density state points. The results agree well with Widom's test particle insertion but show at very high densities significantly smaller statistical uncertaint
Tomohiro Harada
Einstein's field equations in general relativity admit a variety of solutions with spacetime singularities. Numerical relativity has recently revealed the properties of somewhat generic spacetime singularities. It has been found that in a variety of systems self-similar solutions can describe asymptotic or intermediate behaviour of more general solutions
Confluence of resonant laser excitation and bi-directional quantum dot nuclear spin polarization
cond-mat.mes-hallC. Latta, A. Högele, Y. Zhao, A. N. Vamivakas
Resonant laser scattering along with photon correlation measurements have established the atom-like character of quantum dots. Here, we present measurements which challenge this identification for a wide range of experimental parameters: the absorption lineshapes that we measure at magnetic fields exceeding 1 Tesla indicate that the nuclear spins polarize by
Shao-Ming Fei, Xianqing Li-Jost
We study quantum states for which the PPT criterion is both sufficient and necessary for separability. We present a class of 3x3 bipartite mixed states and show that these states are separable if and only if they are PPT.
C. Rechatin, X. Davoine, A. Lifschitz, A. Ben Ismail
Beam loading is the phenomenon which limits the charge and the beam quality in plasma based accelerators. An experimental study conducted with a laser-plasma accelerator is presented. Beam loading manifests itself through the decrease of the beam energy, the reduction of dark current and the increase of the energy spread for large beam charge. 3D PIC simulat
C. Amsler, K. Bösiger, V. Chiochia, W. Erdmann
The Compact Muon Solenoid experiment at the Large Hadron Collider at CERN includes a silicon pixel detector as its innermost component. Its main task is the precise reconstruction of charged particles close to the primary interaction vertex. This paper gives an overview of the mechanical requirements and design choices for the barrel pixel detector. The dist
A. O. Sboychakov, K. I. Kugel, A. L. Rakhmanov, D. I. Khomskii
Spin-state transitions, observed in many transition metal compounds containing Co$^{3+}$ and Fe$^{2+}$, may occur with the change of temperature, pressure, but also with doping, in which case the competition of single-site effects and kinetic energy of doped carriers can favor a change in the spin state. We consider this situation in a simple model, formally
Boris V. Alexeev
This paper was initiated by publication of Ref. [1] and can be considered as Comments on Ref. [1]. Authors of Ref. [1] investigate analytically the propagation of sound waves in one component monatomic gas (especially for the intermediate Knudses number region) using methods of local kinetic description in area where they are not applied in principal. [1] Na
Pattern speed of main spiral arms in NGC 2997: Estimate based on very young stellar complexes
astro-ph.GAP. Grosbol H. Dottori
Deep JHK-Brg photometry of the southern arm of the grand-design spiral galaxy NGC 2997 was obtained by ISAAC/VLT. All sources in the field brighter than K=19 mag were located. Color-color diagrams were used to identify young stellar complexes among the extended sources. Ages can be estimated for the youngest complexes and correlated with azimuthal distances
Giulio Manzonetto
In this paper we briefly summarize the contents of Manzonetto's PhD thesis which concerns denotational semantics and equational/order theories of the pure untyped lambda-calculus. The main research achievements include: (i) a general construction of lambda-models from reflexive objects in (possibly non-well-pointed) categories; (ii) a Stone-style represe
Robert Peters, Thomas Pruschke
We calculate the magnetic phase diagram of the Hubbard model for a Bethe lattice with nearest neighbour (NN) hopping $t_1$ and next nearest neighbour (NNN) hopping $t_2$ in the limit of infinite coordination. We use the amplitude $t_2/t_1$ of the NNN hopping to tune the density of states (DOS) of the non-interacting system from a situation with particle-hole
Comments on "The Euclidean gravitational action as black hole entropy, singularities, and spacetime voids" by C. Castro, J. Math. Phys., 49, 042501, 2008
physics.gen-phAbhas Mitra
We point out that the {\em spacetime void} inferred by Castro[J. Math. Phys. 49, 042501, (2008)] results from his choice of a discontinuous radial gauge. Further since the integration constant $\alpha_0 = 2M_0$ ($G=c=1$) occurring in the vacuum Hilbert/Schwarzschild solution of a neutral "point mass" is zero [Arnowitt et al., in Gravitation: An Introduction
Angeliki Papana, Dimitris Kugiumtzis
We study some of the most commonly used mutual information estimators, based on histograms of fixed or adaptive bin size, $k$-nearest neighbors and kernels, and focus on optimal selection of their free parameters. We examine the consistency of the estimators (convergence to a stable value with the increase of time series length) and the degree of deviation a
On the origin of Fanaroff-Riley classification of radio galaxies: Deceleration of supersonic radio lobes
astro-ph.GANozomu Kawakatu, Motoki Kino, Hiroshi Nagai
We argue that the origin of "FRI/FRI{-.1em}I dichotomy" -- the division between Fanaroff-Riley class I (FRI) with subsonic lobes and class I{-.1em}I (FRI{-.1em}I) radio sources with supersonic lobes is sharp in the radio-optical luminosity plane (Owen-White diagram) -- can be explained by the deceleration of advancing radio lobes. The deceleration is
Chong-Xing Yue, Yong-Zhi Wang, Wei Lui, Wei Ma
The T-odd leptons predicted by the littlest $Higgs$ model with T-parity can be pair produced via the subprocesses $gg\to \ell^{+}_{H}\ell^{-}_{H}$, $q\bar{q}\to \ell^{+}_{H}\ell^{-}_{H}$, $γγ\to \ell^{+}_{H}\ell^{-}_{H}$ and $ VV \to \ell^{+}_{H}\ell^{-}_{H}$ ($V$=$W$ or $Z$) at the $CERN$ Large Hadron Collider $(LHC)$. We estimate the hadronic production cr
Orlando Alvarez, Paul Windey
We derive a cohomological formula for the analytic index of the Dirac-Ramond operator and we exhibit its modular properties.
Oana Ivanovici
We are interested in this article in investigating the smoothing effect properties of the solutions of the Schrodinger equation. We deduce global well-posedness results for the cubic Schrodinger equation in the exterior of several convex obstacles of R^{3}.
Jin-ichi Itoh, Kazuyoshi Kiyohara
We show that some riemannian manifolds diffeomorphic to the sphere have the property that the cut loci of general points are smoothly embedded closed disks of codimension one. Ellipsoids with distinct axes are typical examples of such manifolds.
Brian M. Kurkoski, Justin Dauwels
A belief-propagation decoder for low-density lattice codes is given which represents messages explicitly as a mixture of Gaussians functions. The key component is an algorithm for approximating a mixture of several Gaussians with another mixture with a smaller number of Gaussians. This Gaussian mixture reduction algorithm iteratively reduces the number of Ga
Yu Luo, Jingjing Zhang, Hongsheng Chen, Lixin Ran
The electromagnetic characteristics of plane-transformed invisibility cloaks are quantitatively studied in this paper. We take elliptical cylindrical cloak as the example, and use an elliptical cylindrical wave expansion method to obtain the scattered field. It is demonstrated that an ideal elliptical cylindrical cloak is inherently visible. Noticeable field
Jack S. Calcut, John D. McCarthy
For a locally path connected topological space, the topological fundamental group is discrete if and only if the space is semilocally simply-connected. While functoriality of the topological fundamental group for arbitrary topological spaces remains an open question, the topological fundamental group is always a homogeneous space.
Raymond L. Speth, Eric Lauga
A recent experiment showed that cylindrical segments of water filling a hydrophilic stripe on an otherwise hydrophobic surface display a capillary instability when their volume is increased beyond the critical volume at which their apparent contact angle on the surface reaches ninety degrees (Gau et al., Science, 283, 1999). Surprisingly, the fluid segments
Ghadamali Bagherikaram, Abolfazl S. Motahari, Amir K. Khandani
In this paper, we consider a scenario where a source node wishes to broadcast two confidential messages for two respective receivers via a Gaussian MIMO broadcast channel. A wire-tapper also receives the transmitted signal via another MIMO channel. It is assumed that the channels are degraded and the wire-tapper has the worst channel. We establish the capaci
Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides
cond-mat.mtrl-sciHanghui Chen, Alexie M. Kolpak, Sohrab Ismail-Beigi
We present an ab initio study of the (001) interfaces between two insulating perovskites, the polar LaAlO3 and the nonpolar SrTiO3. We observe an insulating-to-metallic transition above a critical LaAlO3 thickness. We explain that the high conductivity observed at the TiO2 /LaO interface and the lack of similar conductivity at the SrO/AlO2 interface are inhe
Masateru Ishiguro, Fumihiko Usui, Yuki Sarugaku, Munetaka Ueno
We analyzed the Subaru/Suprime-Cam images of 73P/Schwassmann-Wachmann 3B and detected no fewer than 154 mini-comets. We applied synchrone-syndyne analysis, modified for rocket effect analysis, to the mini-fragment spatial distribution. We found that most of these mini-comets were ejected from fragment B by an outburst occurring around 1 April 2006. The ratio
Bipin Singh Koranga
Current neutrino experimental data on neutrino mixing are well describes by Tri-bi-maximal mixing, which is predicts sin^{2}θ_{12}=1/3,zero U_{e3} and θ_{23}=45^{o}. We consider the planck scale operator on neutrino mixing. We assume that the neutrino masses and mixing arise through physics at a scale intrimediate between planck scale and the electroweak bra
Y. Han, W. Y. Li, L. X. Cao, S. Zhang
FeSex (x = 0.80, 0.84, 0.88, 0.92) thin films were prepared on SrTiO3(001) (STO), (La,Sr)(Al,Ta)O3(001) (LSAT), and LaAlO3(001) (LAO) substrates by pulsed laser deposition method. All thin films show single-phase and c-axis oriented epitaxial growth, and are superconducting. Among them, the FeSe0.88 thin films show Tc, onset of 11.8 K and Tc, 0 of 3.4 K. The
T. Klahn, C. D. Roberts, D. B. Blaschke, F. Sandin
One of the key ingredients to understand the properties of neutrons stars is the equation of state at finite densities far beyond nuclear saturation. Investigating the phase structure of quark matter that might be realized in the core of NS inspires theory and observation. We discuss recent results of our work to point out our view on challenges and possibil
Yi-Dong Shen, Jia-Huai You, Li-Yan Yuan
This paper studies the stable model semantics of logic programs with (abstract) constraint atoms and their properties. We introduce a succinct abstract representation of these constraint atoms in which a constraint atom is represented compactly. We show two applications. First, under this representation of constraint atoms, we generalize the Gelfond-Lifschit
Wei Fan
The Tc map in parameter space of electron-phonon interaction $λ$ and phonon frequency $Ω$ is used to classify already known superconductors. The Tc map is partitioned into six regions based on superconductors parameters $λ$ and $Ω$, We briefly discuss the properites of superconductors in evey regionm The Tc map can be used as a useful tool to find and design
Restricted isometry property of matrices with independent columns and neighborly polytopes by random sampling
math.PRRadosław Adamczak, Alexander E. Litvak, Alain Pajor, Nicole Tomczak-Jaegermann
This paper considers compressed sensing matrices and neighborliness of a centrally symmetric convex polytope generated by vectors $\pm X_1,...,\pm X_N\in\R^n$, ($N\ge n$). We introduce a class of random sampling matrices and show that they satisfy a restricted isometry property (RIP) with overwhelming probability. In particular, we prove that matrices with i
Modeling Nuclear Pasta and the Transition to Uniform Nuclear Matter with the 3D Skyrme-Hartree-Fock Method at Finite Temperature I: Core-Collapse Supernovae
astro-ph.SRW. G. Newton J. R. Stone
The first results of a new three-dimensional, finite temperature Skyrme-Hartree-Fock+BCS study of the properties of inhomogeneous nuclear matter at densities and temperatures leading to the transition to uniform nuclear matter are presented. Calculations are carried out in a cubic box representing a unit cell of the locally periodic structure of the matter.
Finding the Brightest Galactic Bulge Microlensing Events with a Small Aperture Telescope and Image Subtraction
astro-ph.GAD. M. Nataf, K. Z. Stanek, G. A. Bakos
Following the suggestion of Gould and Depoy (1998) we investigate the feasibility of studying the brightest microlensing events towards the Galactic bulge using a small aperture (~10 cm) telescope. We used one of the HAT telescopes to obtain 151 exposures spanning 88 nights in 2005 of an 8.4x8.4 square degree FOV centered on (l,b) = (2.85, -5.00). We reduced
Vito Di Benedetto, John Hauptman, Anna Mazzacane
The 4th detector is rich in particle identification measurements from the dual-readout calorimeters, the cluster-timing tracking chamber, the muon spectrometer, and combinations of these systems. In all, a total of 13 measurements contribute to the identification of all partons of the standard model.
C. J. Cotter, D. A. Ham, C. C. Pain
We introduce a mixed discontinuous/continuous finite element pair for ocean modelling, with continuous quadratic pressure/layer depth and discontinuous velocity. We investigate the finite element pair applied to the linear shallow-water equations on an f-plane. The element pair has the property that all geostrophically balanced states which strongly satisfy
Capacitance measurements and electrostatic calibrations in experiments measuring the Casimir force
quant-phR. S. Decca, E. Fischbach, G. L. Klimchitskaya, D. E. Krause
We compare the results of capacitance measurements in the lens-plane and sphere-plane configurations with theoretical predictions from various models of a spherical surface. It is shown that capacitance measurements are incapable of discriminating between models of perfect and modified spherical surfaces in an experiment demonstrating the anomalous scaling l
Tobias Dyckerhoff
We study the category of matrix factorizations associated to the germ of an isolated hypersurface singularity. This category is shown to admit a compact generator which is given by the stabilization of the residue field. We deduce a quasi-equivalence between the category of matrix factorizations and the dg derived category of an explicitly computable dg alge
LIGO Scientific Collaboration, B. Abbott
We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper lim
Aram Galstyan
The problem of multi-agent learning and adaptation has attracted a great deal of attention in recent years. It has been suggested that the dynamics of multi agent learning can be studied using replicator equations from population biology. Most existing studies so far have been limited to discrete strategy spaces with a small number of available actions. In m
Manuel Calixto, Julio Guerrero, Juan Carlos Sánchez-Monreal
Using Coherent-State (CS) techniques, we prove a sampling theorem for holomorphic functions on the hyperboloid (or its stereographic projection onto the open unit disk $\mathbb D_1$), seen as a homogeneous space of the pseudo-unitary group SU(1,1). We provide a reconstruction formula for bandlimited functions, through a sinc-type kernel, and a discrete Fouri
Fabian Schmidt, Eduardo Rozo, Scott Dodelson, Lam Hui
Only galaxies bright enough and large enough to be unambiguously identified and measured are included in galaxy surveys used to estimate cosmic shear. We demonstrate that because gravitational lensing can scatter galaxies across the brightness and size thresholds, cosmic shear experiments suffer from lensing bias. We calculate the effect on the shear power s
Jorge Ananias Neto
We propose a systematic procedure that solves the Dirac bracket commutators. The method is based on the Gauge Unfixing formalism, a procedure that converts second class systems into first class ones without the enlargement of the original phase space variables. We verify that the gauge invariant variables satisfy the Dirac bracket when we strongly impose the
Fabian Schmidt, Eduardo Rozo, Scott Dodelson, Lam Hui
Only certain galaxies are included in surveys: those bright and large enough to be detectable as extended sources. Because gravitational lensing can make galaxies appear both brighter and larger, the presence of foreground inhomogeneities can scatter galaxies across not only magnitude cuts but also size cuts, changing the statistical properties of the result
Rao Zhou, Ramdas S. Pophale, Michael W. Deem
We define a new parameter to quantify the antigenic distance between two H3N2 influenza strains: we use this parameter to measure antigenic distance between circulating H3N2 strains and the closest vaccine component of the influenza vaccine. For the data between 1971 and 2004, the measure of antigenic distance correlates better with efficacy in humans of the
J. D. Hartman, G. Á. Bakos, G. Torres, Géza Kovács
We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V=12.8 K4 dwarf GSC 03033-00706, with a period P = 3.2130598 +- 0.0000021 d, transit epoch Tc = 2454419.19556 +- 0.00020 (BJD) and transit duration 0.0974 +- 0.0006 d. The host star has a mass of 0.73 +- 0.02 Msun, radius of 0.70 +- ^0.02_0.01 Rsun, effecti
Luchezar L. Avramov, Srikanth B. Iyengar, Joseph Lipman
A notion of rigidity with respect to an arbitrary semidualizing complex C over a commutative noetherian ring R is introduced and studied. One of the main result characterizes C-rigid complexes. Specialized to the case when C is the relative dualizing complex of a homomorphism of rings of finite Gorenstein dimension, it leads to broad generalizations of theor
Alexei Borodin, Patrik L. Ferrari, Tomohiro Sasamoto
We consider the TASEP on Z with two blocks of particles having different jump rates. We study the large time behavior of particles' positions. It depends both on the jump rates and the region we focus on, and we determine the complete process diagram. In particular, we discover a new transition process in the region where the influence of the random and dete
Douglas Lundholm
A weighted Hilbert space approach to the study of zero-energy states of supersymmetric matrix models is introduced. Applied to a related but technically simpler model, it is shown that the spectrum of the corresponding weighted Hamiltonian simplifies to become purely discrete for sufficient weights. This follows from a bound for the number of negative eigenv
Collective modes and superflow instabilities of strongly correlated Fermi superfluids
cond-mat.supr-conR. Ganesh, A. Paramekanti, A. A. Burkov
We study the superfluid phase of the one-band attractive Hubbard model of fermions as a prototype of a strongly correlated s-wave fermion superfluid on a lattice. We show that the collective mode spectrum of this superfluid exhibits, in addition to the long wavelength sound mode, a sharp roton mode over a wide range of densities and interaction strengths. We
Michael Ambroso, Burt Ovrut
E8 x E8 heterotic string and M-theory, when compactified on a Calabi-Yau threefold admitting an SU(4) vector bundle with Wilson lines, can give rise to the exact MSSM spectrum with three right-handed neutrino chiral superields, one per family. Rank preserving Wilson lines require that the standard model group be augmented by a gauged U(1)_B-L. Since there ar
Quadrupolar correlations and spin freezing in S = 1 triangular lattice antiferromagnets
cond-mat.str-elE. M. Stoudenmire, Simon Trebst, Leon Balents
Motivated by experiments on NiGa2S4, we discuss characteristic (finite temperature) properties of spin S = 1 quantum antiferromagnets on the triangular lattice. Several recent theoretical studies have suggested the possibility of quadrupolar (spin-nematic) ground states in the presence of sufficient biquadratic exchange. We argue that quadrupolar correlation
George Georgiou
The present study illuminates the relation between null cusped Wilson loops and their corresponding amplitudes. We find that, compared to the case with no self-crossing, the one loop expectation value of a self-intersecting Wilson loop develops an additional 1/εsingularity associated to the intersection. Interestingly, the same 1/εpole exists in the finite p
P. -P. Cortet, D. Bonamy, F. Daviaud, O. Dauchot
We confront a recent visco-plastic description of dense granular flows [P. Jop et al, Nature, {\bf 441} (2006) 727] with multi-directional inhomogeneous steady flows observed in non-smooth contact dynamics simulations of 2D half-filled rotating drums. Special attention is paid to check separately the two underlying fundamental statements into which the consi
Generalized Dynamical Spin Chain and 4-Loop Integrability in N=6 Superconformal Chern-Simons Theory
hep-thDongsu Bak, Hyunsoo Min, Soo-Jong Rey
We revisit unitary representation of centrally extended (2 | 2) excitation superalgebra. We find most generally that `pseudo-momentum', not lattice momentum, diagonalizes spin chain Hamiltonian and leads to generalized dynamic spin chain. All known results point to lattice momentum diagonalization for N=4 super Yang-Mills theory. Having different interac
Y. Charles Li, Zhiwu Lin
Sommerfeld paradox roughly says that mathematically Couette linear shear is linearly stable for all Reynolds number, but experimentally arbitrarily small perturbations can induce the transition from the linear shear to turbulence when the Reynolds number is large enough. The main idea of our resolution of this paradox is to show that there is a sequence of l
Cenke Xu
We study the classical and quantum phase transitions of Sp(4) spin systems on three dimensional stacked square and triangular lattices. We present general Ginzburg-Landau field theories for various types of Sp(4) spin orders with different ground state manifolds such as CP(3), S^7/Z_2, Grassmann manifold G_{2,5}, G_{2,6} and so on, based on which the nature
M. C. B. Abdalla, J. A. Helayël-Neto, Daniel L. Nedel, Carlos R. Senise
We reassess the method of the linear delta expansion for the calculation of effective potentials in superspace, by adopting the improved version of the super-Feynman rules in the framework of the O'Raifeartaigh model for spontaneous supersymmetry breaking. The effective potential is calculated using both the fastest apparent convergence and the principle
Mustafa Sarisaman
We discuss the target space pseudoduality in supersymmetric sigma models on symmetric spaces using two different methods, orthonormal coframe and component expansion. These two methods yield similar results to the classical cases with the exception that commuting bracket relations in classical case turns out to be anticommuting ones because of the appearance
Federico Nguyen
The KLOE experiment operating at the $\phi$--factory DA$\Phi$NE has collected an integrated luminosity of about 2.5 fb$^{-1}$ and 250 pb$^{-1}$, on and off the $\phi$ meson peak respectively. Recent results achieved from studying properties of pseudoscalar and scalar mesons are presented.
Jaume Gomis, Takuya Okuda, Diego Trancanelli
We provide a quantum path integral definition of an 't Hooft loop operator, which inserts a pointlike monopole in a four dimensional gauge theory. We explicitly compute the expectation value of the circular 't Hooft operators in N=4 super Yang-Mills with arbitrary gauge group G up to next to leading order in perturbation theory. We also compute in the strong
Eva Pavarini, Erik Koch
The origin of the cooperative Jahn-Teller distortion and orbital-order in LaMnO3 is central to the physics of the manganites. The question is complicated by the simultaneous presence of tetragonal and GdFeO3-type distortions and the strong Hund's rule coupling between e_g and t_2g electrons. To clarify the situation we calculate the transition temperatur
Andreas Christ, Kaisa Laiho, Andreas Eckstein, Thomas Lauckner
The propagation of several spatial modes has a significant impact on the structure of the emission from parametric down-conversion in a nonlinear waveguide. This manifests itself not only in the spatial correlations of the photon pairs but also, due to new phase-matching conditions, in the output spectrum, radically altering the degree of entanglement within
Anomalous suppression of the Bose glass at commensurate fillings in the disordered Bose-Hubbard model
cond-mat.quant-gasFrank Krüger, Jiansheng Wu, Philip Phillips
We study the weakly disordered Bose-Hubbard model on a cubic lattice through a one-loop renormalization group analysis of the corresponding effective field theory which is explicitly derived by combining a strong-coupling expansion with a replica average over the disorder. The method is applied not only to generic uncorrelated on-site disorder but also to si
Chris Hull, Barton Zwiebach
The zero modes of closed strings on a torus --the torus coordinates plus dual coordinates conjugate to winding number-- parameterize a doubled torus. In closed string field theory, the string field depends on all zero-modes and so can be expanded to give an infinite set of fields on the doubled torus. We use the string field theory to construct a theory of m
Christina V. Kraus, Norbert Schuch, Frank Verstraete, J. Ignacio Cirac
We introduce a family of states, the fPEPS, which describes fermionic systems on lattices in arbitrary spatial dimensions. It constitutes the natural extension of another family of states, the PEPS, which efficiently approximate ground and thermal states of spin systems with short-range interactions. We give an explicit mapping between those families, which
Indranil Biswas, Amit Hogadi
We compute the Brauer group of the moduli stack of stable PGL(r)-bundles on a curve $X$ over an algebraically closed field of characteristic zero. We also show that the Brauer group of such a moduli stack coincides with the Brauer group of the smooth locus of the corresponding coarse moduli space of stable PGL(r)-bundles on $X$.
A. Deuzeman, M. P. Lombardo, E. Pallante
We discuss the existence of a conformal phase in SU(N) gauge theories in four dimensions. In this lattice study we explore the model in the bare parameter space, varying the lattice coupling and bare mass. Simulations are carried out with three colors and twelve flavors of dynamical staggered fermions in the fundamental representation. The analysis of the ch
John D. Mason
We consider a solution to the mu problem in the context of Non-Minimal Gauge Mediation with two Singlets and Low-Scale Messengers. This solution reduces tuning associated with the "Little Hierarchy" problem by permitting a naturally small mu term (100-300 GeV) due to small mixing between the Singlets. The smallness of mu also relies crucially on comp
Gleb Arutyunov, Sergey Frolov
We utilize the DHM integral representation for the BES dressing factor of the world-sheet S-matrix of the AdS_5xS^5 light-cone string theory, and the crossing equations to fix the principal branch of the dressing factor on the rapidity torus. The results obtained are further used, in conjunction with the fusion procedure, to determine the bound state dressin
Naoki Imai
We classify the filtered modules with coefficients corresponding to two-dimensional potentially semi-stable $p$-adic representations of the absolute Galois groups of $p$-adic fields under the assumptions that $p$ is odd and the coefficients are large enough.
Controllability and Observability of Multi-Spin Systems: Constraints by Symmetry and by Relaxation
quant-phU. Sander, T. Schulte-Herbrueggen
We investigate the universality of multi-spin systems in architectures of various symmetries of coupling type and topology. Explicit reachability sets under symmetry constraints are provided. Thus for a given (possibly symmetric) experimental coupling architecture several decision problems can be solved in a unified way: (i) can a target Hamiltonian be simul
Masato Mimura
Let B be any Lp space for p in (1,infty) or any Banach space isomorphic to a Hilbert space, and k be a nonnegative integer. We show that if n is at least 4, then the universal lattice Gamma =SL_n (Z[x1,...,xk]) has property (F_B) in the sense of Bader--Furman--Gelander--Monod. Namely, any affine isometric action of Gamma on B has a global fixed point. The pr
Dan Edidin, Tyler J. Jarvis, Takashi Kimura
We give a purely equivariant construction of orbifold products for quotient Deligne-Mumford stacks [X/G] where G is an arbitrary linear algebraic group (not necessarily finite). The key to our construction is the definition of the "logarithmic trace" of an equivariant vector bundle. We also prove that there is an orbifold Chern character homomorphism which i
Testing the Dark Matter Interpretation of the PAMELA Excess through Measurements of the Galactic Diffuse Emission
astro-ph.GAMarco Regis, Piero Ullio
We propose to test the dark matter (DM) interpretation of the positron excess observed by the PAMELA cosmic-ray (CR) detector through the identification of a Galactic diffuse gamma-ray component associated to DM-induced prompt and radiative emission. The goal is to present an analysis based on minimal sets of assumptions and extrapolations with respect to lo
Peng-fei Yin, Jia Liu, Shou-hua Zhu
The $ O(GeV)$ extra $ U(1)$ gauge boson named U-boson, has been proposed to mediate the interaction among leptons and dark matter (DM), in order to account for the observations by PAMELA and ATIC. In such kind of models, the extra U(1) gauge group can be chosen as $U(1)_{L_i-L_j}$ with $L_i$ the $i-$th generation lepton number. This anomaly-free model provid
Manuel Stadlbauer
We introduce a relative notion of the 'big images and preimages'-property for random topological Markov chains. This then implies that a relative version of the Ruelle-Perron-Frobenius theorem holds with respect to summable and locally Hoelder continuous potentials.
S. Taubenberger, S. Valenti, S. Benetti, E. Cappellaro
In order to assess qualitatively the ejecta geometry of stripped-envelope core-collapse supernovae, we investigate 98 late-time spectra of 39 objects, many of them previously unpublished. We perform a Gauss-fitting of the [O I] 6300, 6364 feature in all spectra, with the position, full width at half maximum (FWHM) and intensity of the 6300 Gaussian as free p
H. Kotegawa, T. Kawazoe, H. Sugawara, K. Murata
We report that the pressure-temperature phase diagram of single-crystalline SrFe$_2$As$_2$ is easily affected by the hydrostaticity of a pressure-transmitting medium. For all of the three mediums we used, superconductivity with zero resistance appears, accompanied by the suppression of an antiferromagnetic (orthorhombic) phase, but the critical pressure $P_c
Mads Engelund, Mads Brandbyge, Antti-Pekka Jauho
We develop a computational method for evaluating the damping of vibrational modes in mono-atomic metallic chains suspended between bulk crystals under external strain. The damping is due to the coupling between the chain and contact modes and the phonons in the bulk substrates. The geometry of the atoms forming the contact is taken into account. The dynamica
Andreas Ipp, Christoph H. Keitel, Jörg Evers
Present ultra-fast laser optics is at the frontier between atto- and zeptosecond photon pulses, giving rise to unprecedented applications. We show that high-energetic photon pulses down to the yoctosecond timescale can be produced in heavy ion collisions. We focus on photons produced during the initial phase of the expanding quark-gluon plasma. We study how
Jorge G. Russo, Paul K. Townsend
We model the situation in which a photon detector moves with constant velocity in a Minkowski heat-bath by considering an Unruh-DeWitt detector, with variable energy gap $\hbar ω$, moving on a brane, at a non-zero (Unruh) temperature $T$ due to acceleration in an orthogonal direction. We compute the angular response for a 2-brane. At low velocity we find agr
Nan Liang, ChangJun Gao, ShuangNan Zhang
We investigate the cosmological evolution of a two-field model of dark energy where one is a dilaton field with canonical kinetic energy and the other is a phantom field with a negative kinetic energy term. A phase-plane analysis shows that the phantom-dominated scaling solution is the stable late-time attractor of this type of models. We find that during th
K. S. Korolev, Mikkel Avlund, Oskar Hallatschek, David R. Nelson
We review and extend results for mutation, selection, genetic drift, and migration in a one-dimensional continuous population. The population is described by a continuous limit of the stepping stone model, which leads to the stochastic Fisher-Kolmogorov-Petrovsky-Piscounov equation with additional terms describing mutations. Although the stepping stone model
Swan Dubois, Maria Potop-Butucaru, Sébastien Tixeuil
Distributed fault-tolerance can mask the effect of a limited number of permanent faults, while self-stabilization provides forward recovery after an arbitrary number of transient fault hit the system. FTSS protocols combine the best of both worlds since they are simultaneously fault-tolerant and self-stabilizing. To date, FTSS solutions either consider stati
Pattern avoidance and smoothness of closures for orbits of a symmetric subgroup in the flag variety
math.RTWilliam M. McGovern, Peter E. Trapa
We give a pattern avoidance criterion to classify the orbits of Sp(p,C) x Sp(q,C) (resp. GL(n,C)) on the flag variety of type C_{p+q} (resp. D_n) with rationally smooth closure. We show that all such orbit closures fiber (with smooth fiber) over a smaller flag variety, and hence are in fact smooth. In addition we prove that the classification is insensitive
Mott transitions in ternary flavor mixtures of ultracold fermions on optical lattices
cond-mat.quant-gasE. V. Gorelik, N. Blümer
Ternary flavor mixtures of ultracold fermionic atoms in an optical lattice are studied in the case of equal, repulsive on-site interactions U>0. The corresponding SU(3) invariant Hubbard model is solved numerically exactly within dynamical mean-field theory using multigrid Hirsch-Fye quantum Monte Carlo simulations. We establish Mott transitions close to int
Kallingalthodi Madhu, K. Narayan
We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyse string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can b
Klaus Bongartz
Let k be an algebraically closed field and A a finite dimensional associative k-algebra. We prove that there is no gap in the lengths of indecomposable A-modules of finite length. The analogous result holds for an abelian k-linear category C if the endomorphism algebras of the simples are k.
Seeing through the String Landscape - a String Hunter's Companion in Particle Physics and Cosmology
hep-thDieter Lust
In this article we will overview several aspects of the string landscape, namely intersecting D-brane models and their statistics, possible model independent LHC signatures of intersecting brane models, flux compactification, moduli stabilization in type II compactifications, domain wall solutions and brane inflation.
Srivatsan Laxman, Basel Shadid, P. S. Sastry, K. P. Unnikrishnan
Engine assembly is a complex and heavily automated distributed-control process, with large amounts of faults data logged everyday. We describe an application of temporal data mining for analyzing fault logs in an engine assembly plant. Frequent episode discovery framework is a model-free method that can be used to deduce (temporal) correlations among events
G. Ramachandran, Venkataraya, J. balasubramanyam
Model independent formulae are derived for the polarizations and spin correlations of protons in the final state of $pp \to ppω$, taking into consideration all the six threshold partial wave amplitudes $f_1, ..., f_6$ covering $Ss, Sp$ and $Ps$ channels. It is shown that these measurements of the final state spin observables, employing only an unpolarized be
M. M. Sheikh-Jabbari, Joan Simon
We analyze SU(2) invariant half-BPS states of the 3d \cN=8 or \cN=6 SCFT within the radial quantization of the ABJM theory, the theory proposed to describe N M2-branes in the R^3x C^4/Z_k background. After studying the classical moduli space of these configurations, we explicitly construct a set of gauge invariant operators involving 't Hooft monopole op
Robert Engström, Tommy Färnqvist, Peter Jonsson, Johan Thapper
A graph homomorphism is a vertex map which carries edges from a source graph to edges in a target graph. The instances of the Weighted Maximum H-Colourable Subgraph problem (MAX H-COL) are edge-weighted graphs G and the objective is to find a subgraph of G that has maximal total edge weight, under the condition that the subgraph has a homomorphism to H; note
Rafael Tumanyan
The quark-gluon sea in the hadrons is considered as periodically correlated. Energy levels of Shrodinger equation with harmonic potential is used for describing of the spectrum of hadron masses. In the considered cases the effective potential operating on each particle of ensemble, under certain conditions becomes square-law on displacement from a equilibriu
Daniel Manzano, Marcin Pawlowski, Caslav Brukner
We consider quantum learning machines -- quantum computers that modify themselves in order to improve their performance in some way -- that are trained to perform certain classical task, i.e. to execute a function which takes classical bits as input and returns classical bits as output. This allows a fair comparison between learning efficiency of quantum and
Giona Veronelli
We prove that, in general, given a $p$-harmonic map $F:M\to N$ and a convex function $H:N\to\mathbb{R}$, the composition $H\circ F$ is not $p$-subharmonic. By assuming some rotational symmetry on manifolds and functions, we reduce the problem to an ordinary differential inequality. The key of the proof is an asymptotic estimate for the $p$-harmonic map under
Betti Hartmann, Farhad Arbabzadah
Motivated by astrophysical observations of excess electronic production in the galaxy, new theoretical models of the dark matter sector have been proposed in which the Standard model couples to the dark matter sector through an attractive interaction. The coupling of the Standard model to "dark strings", which are solutions of the low energy dark sec
Janusz Grabowski, Marek Kus, Giuseppe Marmo
We consider transformation maps on the space of states which are symmetries in the sense of Wigner. Due to the convex nature of the space of states, the set of these maps has a convex structure. We investigate the possibility of a complete characterization of extreme maps of this convex body, to be able to contribute to the classification of positive maps. O